Andrzej Badeński of Poland, who had won bronze in 1964, was the only finalist from the Tokyo Games to compete again in 1968.

The United States team was "dominant in this event in 1968"; Larry James held the world record at 44.1 seconds, Lee Evans was the AAU and NCAA champion, and even the third member of the team, Ron Freeman, ran well below Olympic record time at the U.S.

[2] Barbados, the Dominican Republic, El Salvador, Morocco, Nicaragua, and Sudan appeared in this event for the first time.

The United States made its sixteenth appearance in the event, the only nation to compete in it at every Olympic Games to that point.

The "fastest loser" system, introduced in 1964, was available but not used in 1968 because there was no need to balance quarterfinals as there were 8 heats in the first round.

Evans nearly withdrew from the final in protest of the expulsion of his college teammates Tommie Smith and John Carlos from the Games after their Black Power salute.